J/A+A/651/L15 Angular-momentum plane for disc galaxies (Mancera Pina+, 2021)
A tight angular-momentum plane for disc galaxies.
Mancera Pina P.E., Posti L., Pezzulli G., Fraternali F., Fall S.M.,
Oosterloo T., Adams E.A.K.
<Astron. Astrophys. 651, L15 (2021)>
=2021A&A...651L..15M 2021A&A...651L..15M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Morphology
Keywords: galaxies: kinematics and dynamics - galaxies: spirals -
galaxies: dwarfs - galaxies: formation - galaxies: evolution -
galaxies: fundamental parameters -
Abstract:
The relations between the specific angular momenta (j) and masses (M)
of galaxies are often used as a benchmark in analytic models and
hydrodynamical simulations as they are considered to be amongst the
most fundamental scaling relations. Using accurate measurements of the
stellar (j*), gas (jgas), and baryonic (jbar) specific angular momenta
for a large sample of disc galaxies, we report the discovery of tight
correlations between j, M, and the cold gas fraction of the
interstellar medium (fgas). At fixed fgas, galaxies follow parallel
power laws in 2D (j, M) spaces, with gas-rich galaxies having a larger
j* and jbar (but a lower jgas) than gas-poor ones. The slopes of the
relations have a value around 0.7. These new relations are amongst the
tightest known scaling laws for galaxies. In particular, the baryonic
relation (jbar-Mbar-fgas), arguably the most fundamental of the three,
is followed not only by typical discs but also by galaxies with
extreme properties, such as size and gas content, and by galaxies
previously claimed to be outliers of the standard 2D j-M relations.
The stellar relation (j*-M*-fgas) may be connected to the known
j*-M* bulge fraction relation; however, we argue that the
jbar-Mbar-fgas relation can originate from the radial variation in the
star formation efficiency in galaxies, although it is not explained by
current disc instability models.
Description:
The galaxies used on one relation are not necessarily used in the
other relations. This is because for each component (stars, gas, and
baryons) we only use the galaxies with convergent stellar/gas/baryonic
specific angular momentum profiles (see Mancera Pina et al.,
2021A&A...647A..76M 2021A&A...647A..76M, Cat. J/A+A/647/A76)., So, for example, a galaxy
with a convergent stellar specific angular momentum profile but
without convergent gas and baryonic specific angular momenta profiles,
would be used when studying the stellar component but not the gas and
baryons. Therefore, such galaxy appear in "stars.dat" but not in
the other two files.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
baryons.dat 89 105 Galaxies used for the baryonic relation
gas.dat 89 87 Galaxies used for the gas relation
stars.dat 89 130 Galaxies used for the stellar relation
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See also:
J/A+A/647/A76 : Disc galaxies baryonic specific ang. mom. (Mancera Pina+, 2021)
Byte-by-byte Description of file: baryons.dat gas.dat stars.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Galaxy ID
12- 19 E8.3 Msun Mass Mass
21- 28 E8.3 Msun e_Mass rms uncertainty on Mass
30- 36 F7.1 kpc.km/s j Specific angular momentum
39- 44 F6.1 kpc.km/s e_j rms uncertainty on j
47- 50 F4.2 --- fgas Gas fraction
53- 56 F4.2 --- e_fgas rms uncertainty on fgas
58- 62 F5.2 kpc Dist Distance
64- 68 F5.2 kpc e_Dist rms uncertainty on Dist
70- 71 I2 --- HT Hubble type (1)
73- 77 F5.2 --- c(lM-lfgas) Correlation coefficient between
uncertainties of log(M) and log(fgas)
79- 83 F5.2 --- c(lM-lj) Correlation coefficient between
uncertainties of log(M) and log(j)
85- 89 F5.2 --- c(lfgas-lj) Correlation coefficient between
uncertainties of log(fgas) and log(j)
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Note (1): Hubble type, trom the SPARC data base and NED, as follows:
0 = S0
1 = Sa
2 = Sab
3 = Sb
4 = Sbc
5 = Sc
6 = Scd
7 = Sd
8 = Sdm
9 = Sm
10 = Im
11 = BCD
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Acknowledgements:
Pavel E. Mancera Pina, pavel(at)astro.rug.nl
(End) Pavel Mancera Pina [Univ. Groningen], Patricia Vannier [CDS] 15-Jul-2021